Inclusion of Untrusted polyfill.io Code Vulnerability in fides.js
Description
Fides is an open-source privacy engineering platform. fides.js, a client-side script used to interact with the consent management features of Fides, used the polyfill.io domain in a very limited edge case, when it detected a legacy browser such as IE11 that did not support the fetch standard. Therefore it was possible for users of legacy, pre-2017 browsers who navigate to a page serving fides.js to download and execute malicious scripts from the polyfill.io domain when the domain was compromised and serving malware. No exploitation of fides.js via polyfill.io has been identified as of time of publication.
The vulnerability has been patched in Fides version 2.39.1. Users are advised to upgrade to this version or later to secure their systems against this threat. On Thursday, June 27, 2024, Cloudflare and Namecheap intervened at a domain level to ensure polyfill.io and its subdomains could not resolve to the compromised service, rendering this vulnerability unexploitable. Prior to the domain level intervention, there were no server-side workarounds and the confidentiality, integrity, and availability impacts of this vulnerability were high. Clients could ensure they were not affected by using a modern browser that supported the fetch standard.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
ethyca-fidesPyPI | < 2.39.1 | 2.39.1 |
Affected products
1Patches
1868c4d629760Remove fetch polyfill from FidesJS (#5026)
2 files changed · +3 −10
CHANGELOG.md+3 −3 modified@@ -23,12 +23,12 @@ The types of changes are: ### Changed - Navigation changes. 'Management' was renamed 'Settings'. Properties was moved to Settings section. [#5005](https://github.com/ethyca/fides/pull/5005) - - -### Changed - Changed discovery monitor form behavior around execution date/time selection [#5017](https://github.com/ethyca/fides/pull/5017) - Changed integration form behavior when errors occur [#5023](https://github.com/ethyca/fides/pull/5023) +### Removed +- Removed the `fetch` polyfill from FidesJS (#5026)[https://github.com/ethyca/fides/pull/5026] + ### Fixed - Fixed intermittent connection issues with Redshift by increasing timeout and preferring SSL in test connections [#4981](https://github.com/ethyca/fides/pull/4981)
clients/privacy-center/pages/api/fides-js.ts+0 −7 modified@@ -271,13 +271,6 @@ export default async function handler( const script = ` (function () { - // This polyfill service adds a fetch polyfill only when needed, depending on browser making the request - if (!window.fetch) { - var script = document.createElement('script'); - script.src = 'https://polyfill.io/v3/polyfill.min.js?features=fetch'; - document.head.appendChild(script); - } - // Include generic fides.js script and GPP extension (if enabled) ${fidesJS}${fidesGPP}${ customFidesCss
Vulnerability mechanics
Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
7- github.com/advisories/GHSA-cvw4-c69g-7v7mghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2024-38537ghsaADVISORY
- fetch.spec.whatwg.orgghsax_refsource_MISCWEB
- github.com/ethyca/fides/commit/868c4d629760572192bd61db34f5a4458ed12005ghsax_refsource_MISCWEB
- github.com/ethyca/fides/pull/5026ghsax_refsource_MISCWEB
- github.com/ethyca/fides/security/advisories/GHSA-cvw4-c69g-7v7mghsax_refsource_CONFIRMWEB
- sansec.io/research/polyfill-supply-chain-attackghsax_refsource_MISCWEB
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